CVE-2024-49049: Microsoft Remote SSH Privilege Escalation

CVE-2024-49049 Overview

CVE-2024-49049 is an Elevation of Privilege vulnerability affecting the Visual Studio Code Remote SSH extension developed by Microsoft. This vulnerability allows a local attacker with low privileges to escalate their privileges on the affected system, potentially gaining unauthorized access to sensitive data and the ability to modify system configurations.

Critical Impact

Local attackers can exploit improper access control mechanisms in the VS Code Remote SSH extension to elevate privileges, potentially compromising confidentiality and integrity of affected systems without user interaction.

Affected Products

• Microsoft Remote SSH extension for Visual Studio Code
• Visual Studio Code installations with Remote SSH extension enabled
• Development environments utilizing VS Code remote development capabilities

Discovery Timeline

• 2024-11-12 - CVE-2024-49049 published to NVD
• 2024-11-18 - Last updated in NVD database

Technical Details for CVE-2024-49049

Vulnerability Analysis

This vulnerability is classified under CWE-284 (Improper Access Control), indicating that the Remote SSH extension fails to properly restrict access to resources or functionality. The flaw enables a local attacker who already has limited access to the system to bypass security controls and obtain elevated privileges.

The attack requires local access to the target system but does not require any user interaction, making it exploitable in automated attack scenarios. While availability is not impacted, successful exploitation results in high impact to both confidentiality and integrity, allowing attackers to access sensitive information and make unauthorized modifications.

Root Cause

The root cause of CVE-2024-49049 lies in improper access control implementation within the Visual Studio Code Remote SSH extension. The extension fails to adequately validate or restrict operations that should require elevated privileges, creating a pathway for privilege escalation.

The CWE-284 classification indicates that the vulnerability stems from the software not restricting or incorrectly restricting access to a resource from an unauthorized actor. This type of flaw typically occurs when permission checks are missing, improperly implemented, or can be circumvented through specific sequences of operations.

Attack Vector

The attack vector for this vulnerability is local, meaning an attacker must have some level of access to the target system to exploit it. The exploitation process involves:

1. Initial Access: Attacker gains low-privilege access to a system running VS Code with the Remote SSH extension
2. Privilege Escalation: Attacker leverages the improper access control flaw to bypass security restrictions
3. Elevated Operations: With escalated privileges, the attacker can access confidential data or modify system integrity

The vulnerability does not require the attacker to trick users into performing actions, as the UI:N component indicates no user interaction is necessary for successful exploitation.

Detection Methods for CVE-2024-49049

Indicators of Compromise

• Unexpected privilege changes or permission modifications associated with VS Code processes
• Anomalous file access patterns originating from the VS Code Remote SSH extension
• Unusual process spawning or execution chains linked to code or VS Code helper processes
• Unauthorized access to sensitive files or directories from low-privilege user contexts

Detection Strategies

• Monitor for unusual activity from VS Code processes, particularly those accessing resources beyond normal development scope
• Implement endpoint detection rules that flag privilege escalation attempts from VS Code-related processes
• Deploy file integrity monitoring on critical system files that may be targeted post-exploitation
• Configure audit logging to capture permission changes and elevated operations from development tools

Monitoring Recommendations

• Enable verbose logging for VS Code extension activity to capture potential exploitation attempts
• Implement process monitoring to detect anomalous behavior from code-server or Remote SSH helper processes
• Monitor for lateral movement attempts that may follow successful privilege escalation
• Review VS Code extension installation and update events for unauthorized modifications

How to Mitigate CVE-2024-49049

Immediate Actions Required

• Update the Microsoft Remote SSH extension to the latest patched version immediately
• Audit systems for any signs of exploitation or unauthorized privilege changes
• Review and restrict unnecessary VS Code extension permissions where possible
• Implement the principle of least privilege for all development workstations

Patch Information

Microsoft has released a security update addressing this vulnerability. Detailed patch information is available through the Microsoft Security Response Center advisory. Organizations should prioritize updating the Remote SSH extension through the VS Code extension marketplace or organizational software distribution mechanisms.

To update the extension:

1. Open Visual Studio Code
2. Navigate to the Extensions view (Ctrl+Shift+X)
3. Locate the Remote - SSH extension
4. Click the Update button if available, or verify the installed version is patched

Workarounds

• Temporarily disable the Remote SSH extension on systems where immediate patching is not feasible
• Restrict local access to development workstations to trusted users only
• Implement network segmentation to limit the impact of potential privilege escalation
• Enable enhanced logging and monitoring on systems with the affected extension while awaiting patches

# Disable the Remote SSH extension via command line (temporary workaround)
code --disable-extension ms-vscode-remote.remote-ssh

# Verify installed extension version
code --list-extensions --show-versions | grep remote-ssh